textproduct: Quad Cities

KEY MESSAGES

- Winter Weather Advisory through tonight expanded south and west for 2 to 4 inches of snow. Evening commutes affected especially along and south of Cedar Rapids to the Quad Cities. - Another clipper system Saturday will bring accumulating snow to portions of the area, especially south of I-80.

- Very cold/arctic air moving in for the weekend. Biting wind chills well below zero Friday and especially Saturday night into Sunday morning with dangerous levels. Temperatures will then moderate into the 30s by Tuesday.

SHORT TERM /THROUGH FRIDAY/

Issued at 245 PM CST Thu Dec 11 2025

Tonight...Clipper system and top-down saturation process incoming as this is typed. Building upon the earlier update discussion, continuing to look at the upstream forcing/F-gen bands and RADAR trends, seems that the southwest third to half of the DVN CWA is in line for the heavier snow amounts and more organized bands through Midnight to 1 AM or so, when it then tapers off and moves out. Thus the earlier southwest expansion to the advisory still looks in line, while the northern periphery row of counties may not get much snow at all now. Sharp cut-offs or gradients on either sides of the banded swath accumulations with this clipper. With the accepted SLR's and assessing the vertical profiles with the extent of forcing, still coming up with 2-4 inches for much of the advisory area and a higher snow axis now looking to occur From Sigourney IA, to Burlington IA, and to Macomb IL. The higher amounts may actually occur acrs portions of west central IL and the southeast corner of the DVN CWA. Interesting that the old omega max/H85 cold/90+ RH rule targets a further south axis of Fairfield IA, to FT MAdison IA, and to southeast of Macomb line. Have already eliminated the freezing main mix, but some spotty ice pellets or a few rain drops still possible acrs the far southern CWA especially in MO but snow remains the main show. The evening crew may be able to trim back the advisory from the north and northeast if this southwest trend continues to verify. Lows tonight in the teens and 20s.

Friday...Secondary weaker wave embedded in broad but progressive northwesterlies acrs much of the mid CONUS, may produce some light snow showers and flurries Friday morning mainly along and north of I80 with a dusting to a few tenths of snow accum possible. Then the rest of the day dry with highs in the 20s.

LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/

Issued at 245 PM CST Thu Dec 11 2025

Late Friday night into Saturday...Here comes the next clipper in the active flow pattern. QPF has inched up some, but fcst soundings showing deep saturation in the dendritic layer along prime LLVL baroclinic path shouts proficient snow maker and high SLR potential during the event. There will be the same game of how far north or south the main band or bands set up, but seems the further south ECMWF and Euro ensembles first on the trend again. These solutions suggest a high end advisory may occur mainly along and south of I80, with the heaviest snow falling Sat morning after 11z thru 18z. Cold post clipper feed Friday night will make for single digit lows Sat morning, with not much recovery during the day with snow and clouds.

Then here comes the arctic high with at least 3 sigma cold coming down for Saturday night into Sunday morning. With the expected snow cover and cold advection from Canada, ambient lows by Sunday morning may range from 5 below to 15 below zero. Northwest sfc winds of 5-10 MPH may make for dangerous wind chills of 20 to 30 below Sunday morning, and thus the eventual need of some type of cold headline. Not quite as cold into Monday morning but still may be 20 below or colder wind chills north of I-80 which may need a headline.

Longer range progs still show flattening steering flow acrs the mid CONUS and thus moderating temps into mid next week...30s to 40s by next Wednesday?

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 609 PM CST Thu Dec 11 2025

A band of accumulating snow has developed across the southern half of the local area, generating IFR to LIFR conditions under it. Farther north, MVFR to VFR conditions were observed. Models seem to be having some difficulty handling the current conditions, especially the LIFR conditions under the band of snow, so uncertainty remains on how things will evolve over the next six hours. Under the band, snowfall rates have been around 0.5 to 0.75 inches per hour, which is expected to gradually weaken after 02z this evening. After the snow ends, we should see some MVFR to IFR ceilings lingering over the area. Light and variable winds are expected tonight through Friday morning before turning northwesterly Friday afternoon and strengthening, with gusts to around 20 knots possible.

DVN WATCHES/WARNINGS/ADVISORIES

IA...Winter Weather Advisory until 3 AM CST Friday for IAZ051-052- 063>065-067-068-076>078-087>089-098-099. IL...Winter Weather Advisory until 3 AM CST Friday for ILZ015-016- 024>026-034-035. MO...None.